A 37-year-old Poweshiek County man died early Sunday when he was thrown from a car during a single-vehicle rollover, authorities said. The accident happened around 3 a.m. near Old Highway 6 and 230th Street in Poweshiek County, according to an Iowa State Patrol crash report. Troopers said the driver, 46-year-old Matthew T. Gibson, of Brooklyn, was traveling west on Old Highway 6 when he failed to negotiate a curve. The car rolled several times before landing in a ditch. The passenger, identified as Jason W. Hayes, of Guernsey, was ejected from the car and died at the scene. Authorities said he was not wearing a seat belt. Gibson, who was wearing a seat belt, was taken to a Grinnell hospital. The extent of his injuries wasn’t immediately known. The crash remains under investigation.